Manganese magnetic properties

L. magnes, magnet, from magnetic properties of pyrolusite It. manganese, corrupt form of magnesia)... 

The physical description of strongly pressure dependent magnetic properties is the object of considerable study. Edwards and Bartel [74E01] have performed the more recent physical evaluation of strong pressure and composition dependence of magnetization in their work on cobalt and manganese substituted invars. Their work contrasts models based on a localized-electron model with a modified Zener model in which both localized- and itinerant-electron effects are incorporated in a unified model. Their work favors the latter model. 

Manganese - the atomic number is 25 and the chemical symbol is Mn. The name derives from the Latin magnes for magnet since pyrolusite (Mn02) has magnetic properties. It was discovered by the Swedish pharmacist and chemist Carl-Wilhelm Scheele in 1774. Also in 1774, the Swedish chemist Johan Gottlieb Gahn first isolated the metal. 

Table 6 Magnetic properties and related parameters for dinuclear manganese(III)-carboxylato complexes.

The Mn- Mn separations in both planar and butterfly complexes are very similar and range between 2.80 A and 3.45 A. The magnetic properties of these complexes have been studied extensively, and showed antiferromagnetic interactions between the manganese(III) centers. Electrochemical behavior of the butterfly conmlexes is summarized in Table 9 and both oxidative and reductive processes are observed. 

Iron and manganese-combine together, forming an alloy whiter and more brittle than iron and when the proportion of manganese is about twenty-two per cent., the alloy ceases to have magnetic properties.—Musket. 

Lis, T., Preparation, structure, and magnetic-properties of a dodecanuclear mixed-valence manganese carboxylate. Acta Crystallogr Sect. B-Struct. Commun. 1980, 36, 2042-2046. 

Janczak J, Kubiak R, Sledz M, Borrmann H, Grin Y (2003) Synthesis, structural investigations and magnetic properties of dipyridinated manganese phthalocyanine, MnPc(py)2. Polyhedron 22 2689-2697... 

In addition to the dilute alloys already discussed, there are a number of alloys of the metals of the platinum group with manganese, iron, cobalt, and nickel which have magnetic properties based on the formation of ordered structures at some particular composition. 

Manganese is famous for its peculiar structure. With n, = 1.15, it follows from Figure 84 that 3 < rhg < 4 in 7-Mn, and therefore that below some critical temperature -hole ordering should induce a f.c.c. —> f.c.tet. (c/a < 1) transformation. The existence of such a transformation and the magnetic properties of the low-temperature phase can be extrapolated from Mn-rich Mn-Cu alloys (35,432). 

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